This invention relates to a skirt board and saddle assembly for bulk material belt-type conveyors, and more particularly to a modular assembly in which the skirt boards are removably and adjustably supported on individual arms which are each associated with one of a plurality of transversely positioned impact frames. Frequently, skirt boards are used at the loading zone, although they may be used at any location along the conveyor belt where edge sealing is desired.
Loading or impact areas on belt-type conveyors, for conveying bulk material such as coal, limestone and the like, commonly employ a pair of elastomeric skirt boards which extend along the sides of the impact zone and parallel to the direction of movement of the belt. The sheet boards guide the material to the center of the belt and away from the edges. Also they seal the impact area from spillage due to fine airborne particles spilling over the edges of the belt.
When skirt boards are used in conjunction with conventional idlers, the skirt boards have difficulty in sealing where the belt sags from one idler to the next, thereby allowing the seal to be broken between the belt and the skirt board rubber. In addition, the user must fabricate some type of a support system to hold the skirt board clamping system in place.
Skirt boards are often used in combination with a chute provided by the user of the belt-type conveyor. Sometimes the skirt boards are actually supported by the delivery chute as illustrated, for example, in U.S. Pat. No. 4,874,082 issued Oct. 17, 1989. Since these skirt boards are supported by the chute, rather than by the troughing support assembly, it is difficult to maintain an adjustment between the skirt board and the underlying running surface of the belt, particularly where the belt is suspended between impact rollers as shown in patent '082.
U.S. Pat. No. 3,499,523 issued Mar. 10, 1970 shows a further example of a skirt board arrangement combined with a conveyor belt supported on spaced impact rollers. The skirt board is supported by some "super structure" above the conveyor belt, but not formed an integral or modular part of the belt troughing and supporting arrangement.
A further example illustrating an arrangement for locating and positioning a pair of opposed skirt boards in relation to the surface of a conveyor belt is shown in U.S. Pat. No. 5,007,528 issued Apr. 16, 1991. In this reference, a longitudinally extending skirt board is mounted on an auxiliary structure by which the entire board moves as a unit, and is weight counter-balanced at one of its ends.
Not all impact zones use impact rollers. Devices known as slider beds have come into use, in which a frame supports a plurality of longitudinally extending individual bars having polymeric exposed upper surfaces across which the belt can slide in a loading zone. British patent 2,188,018 published Sept. 23, 1987 illustrates one such slider trough and also illustrates in phantom in FIG. 3, a pair of flexible skirt boards 29 supported from the lower lip of an overhead feed trough. In U.S. Pat. No. 4,789,056 issued Dec. 6, 1988, a slider bed is shown with trough-like side plates supported from the troughing frames positioned at either side of the belt, but no skirt board arrangement, as such, is disclosed.